1. Field
The disclosed subject matter relates to devices, systems, and processes useful as a control for a vehicle engine when a torque convertor lock-up clutch is engaged.
2. Description of the Related Art
Existing vehicles powered by an internal combustion engine use various types of transmission systems for transmitting the power created by the engine to the drive wheel(s) of the vehicle. For example, an automatic transmission can be used that shifts gear ratios without direct input from the operator of the vehicle. Alternatively, semi-automatic transmissions are known that can shift gear ratios with or without direct input from the operator. In conjunction with these types of transmissions, an electronic control unit can be used to control when and which gear ratio is engaged based on any combination of inputs, such as, but not limited to gear selector position, throttle position, engine load, and vehicle speed.
A torque converter can be coupled between the engine and the automatic or semi-automatic transmission in order to multiply the torque output from the engine as well as to provide a fluid slip coupling that allows the crankshaft to rotate at a different rate than the input to the transmission (which allows the vehicle to idle). In order to improve fuel efficiency, the torque converter can include a lock-up clutch that can by-pass the fluid coupling of the torque converter. This can reduce energy loss via fluid friction within the fluid of the torque converter, thus improving fuel economy of the vehicle.
The same electronic control unit (or a different electronic control unit) can be used to determine the timing and to affect the engagement/disengagement of the lock-up clutch. As such, the operator does not need to decide when engagement/disengagement is appropriate. Additionally, it is not necessary for the operator to be notified of or to perceive actuation of the lock-up clutch.
There is a need to provide a control system and method to more efficiently cause the actuation of the lock-up clutch with a level of manipulation that can be imperceptible or minimally perceptible to the operator and/or any passenger(s) of the vehicle.